Various apparatuses and methods have been developed for utilizing solvents, usually hot, aqueous mixtures and/or steam, in cleaning rugs, upholstery, drapes, and the like in situ by means of hand-operated nozzles connected to the solvent supply and a suction source so as to withdraw soil-contaminated solvent from the work over which the nozzle is passed. An example of such apparatus and method is disclosed in Thompson et al. U.S. Pat. No. 3,559,220. Such devices, however, do not as effectively remove some soil as does dry cleaning equipment, require a substantial drying period, and are damaging to certain fabrics. Sixty percent of the drapery and upholstery fabrics in use now require dry cleaning, so there is a substantial unfilled demand for equipment which will dry clean such fabrics in situ.
Conventional commercial dry cleaning equipment and processes have been developed to a high degree of efficiency. However, such methods require large and expensive closed systems for recirculation and purification of large quantities of expensive and sometimes flammable and/or toxic solvents. Accordingly, conventional dry cleaning methods normally are limited to the cleaning of items which can be placed inside the cleaning vessel at the commercial establishment and, therefore, are not adapted for portability or cleaning of articles in situ. Moreover, articles such as clothing requiring dry cleaning, usually are sent to the cleaner fairly often so that the soils and stains therein are relatively fresh. However, heavy drapes and furniture normally remain in service over much longer periods of time, so that the stains and soils therein become set and, therefore, require longer and more effective cleaning methods. In a professional cleaning plant, a soiled item can be held longer in the wheeled vat or subjected successively to different solvent baths, if necessary. Thus, the dry cleaning of fabrics in situ, particularly with the use of suction-nozzle-type devices which provide a very short cleaning period and which are safe for use in the open atmosphere, have not been practically developed.
Accordingly, an object of the present invention is to provide a portable, compact, economical, safe, and highly efficient method of dry cleaning of fabrics in situ which is sufficiently uncomplicated for use by nonprofessionals, if desired.
A more specific object is to provide a method of dry cleaning of fabrics utilizing a novel, highly efficient solvent which is safe to use in the open atmosphere and without recirculation.